How many times have you been running around town only to realize your cell phone has about 10 percent of its battery life left and you still need it to get you through the night? Instead of trying to find the nearest Starbucks to recharge your phone, why not just plug it into your backpack? For the eighth day of our Better Than Socks Holiday Giveaway, we’re offering the rechargeable Powerbag Business Class Pack, armed with a built-in 6000mAH battery.

When fully charged, the Powerbag lets you charge your smartphone up to four times. It includes Apple, micro-USB, and mini-USB connectors, and a USB port, making it possible to charge hundreds of different devices, including all versions of the Kindle, the Nook, the Samsung Galaxy Tab, the iPad, iPod touch, iPhone, and iPod nano. The bag can hold up to a 15-inch laptop, and also has a dedicated tablet compartment.

Pressing the logo button quickly will let you see how much power you have left. When it’s time to recharge the bag, simply plug it into a wall outlet using its water-resistant AC adapter. Made with traveling in mind, the Powerbag has a checkpoint friendly FlyFlat design, so there’s no need to remove your laptop while going through airport security.

Want to travel in style without ever having to worry about being without power? Just leave us a comment below with where you plan on taking the bag if you win. The contest ends Monday, December 24 [now closed], and we’ll notify the winner the following day.